On 10/12/2017 02:40 PM, Dilip Kumar wrote: > On Thu, Oct 12, 2017 at 4:31 PM, Tomas Vondra > <tomas.von...@2ndquadrant.com> wrote: >> Hi, >> >> It seems that Q19 from TPC-H is consistently failing with segfaults due >> to calling tbm_prepare_shared_iterate() with (tbm->dsa==NULL). >> >> I'm not very familiar with how the dsa is initialized and passed around, >> but I only see the failures when the bitmap is constructed by a mix of >> BitmapAnd and BitmapOr operations. >> > I think I have got the issue, bitmap_subplan_mark_shared is not > properly pushing the isshared flag to lower level bitmap index node, > and because of that tbm_create is passing NULL dsa while creating the > tidbitmap. So this problem will come in very specific combination of > BitmapOr and BitmapAnd when BitmapAnd is the first subplan for the > BitmapOr. If BitmapIndex is the first subplan under BitmapOr then > there is no problem because BitmapOr node will create the tbm by > itself and isshared is set for BitmapOr. > > Attached patch fixing the issue for me. I will thoroughly test this > patch with other scenario as well. Thanks for reporting. >
Yep, this fixes the failures for me. regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
